A conventional arc monitor system is configured to use a general CCTV camera to detect arc light on a generation of an arc, and locates a block of a located place of the failure point based on a screen of a single image (refer to Patent Document 1, for example).
However, it is not possible to cause an aperture value of a lens to optimally respond to a momentary light emission caused by an arc current (to close the aperture), and a captured image of the arc discharge thus results in a saturated white image in most cases.
Patent Document 1: JP 11-98628 A